Gas turbine engines are used frequently in ground vehicles, and particularly in military vehicles, such as armored tanks and armored personnel carriers. Vehicles of this type frequently will be used in rugged terrain and under a variety of adverse environmental and climatic conditions. For example, the vehicles are likely to place a substantial amount of dust and debris in the surrounding air. These dust and dirt particles could cause significant damage to the rotors of the compressor and turbine. Consequently it is necessary to thoroughly filter the air being drawn into the gas turbine engine. It also is necessary to periodically clean the filters to ensure a sufficient flow of air into the gas turbine engine.
The typical prior art inlet filter system for gas turbine engines on land vehicles has included a generally planar filter mounted in a plenum chamber disposed adjacent the engine. Air is drawn into the plenum chamber and must pass through the filter prior to entering the gas turbine engine. Periodically the filter must be cleaned or replaced. The cleaning procedure may vary depending upon the physical characteristics of the filter medium. For example, some filters must be removed and agitated to shake dust particles free of the filter medium. Other filters utilize a fluid such as water or compressed air to blow trapped particles from the filter. Still other filters utilize a vacuum or a combination of a blower and a vacuum. Many of the prior art filters utilize a blower apparatus and/or a vacuum apparatus which are movable relative to the filter. These blower/vacuum structures will periodically be activated to move across the filter surface to carry out a cleaning operation. Still other inlet filters will employ a plurality of planar filters angularly mounted relative to one another, such as in the form of a letter "V" or "W."
The prior art air inlet filters for gas turbine engines in ground vehicles have had several significant deficiencies. The most significant of these deficiencies has been the large amount of space required for the filter structure. This excessive space is a particular problem in military vehicles such as tanks and armored personnel carriers where space is at a premium. Specifically, the excessive space allotted to a large air inlet filter could otherwise be devoted to military personnel, ammunition, electronic equipment and the like.
The prior art structures and methods for cleaning air inlet filters also have been deficient. Specifically, systems requiring complete replacement of the filter or manual cleaning thereof are inconvenient in most environments and totally unacceptable under combat conditions. Systems that utilize movable sources of air pressure or vacuum to clean the filter overcome certain of the problems associated with manual cleaning or replacement. However, it has been found difficult to achieve a high degree of reliability on the complex movable sources of air pressure or vacuum. Furthermore, these movable sources of air pressure or vacuum are extremely complex and costly and can add significantly to the already excessive space requirements of the inlet filter system.
Accordingly, it is an object of the subject invention to provide an improved air inlet filter for gas turbine engines employed in ground vehicles.
It is another object of the subject invention to provide an air inlet filter for a gas turbine engine that substantially reduces the space requirements of the combined engine and filter system.
It is an additional object of the subject invention to provide an air inlet filter for a gas turbine engine with an efficient filter cleaning mechanism.
It is a further object of the subject invention to provide an air inlet filter for a gas turbine engine with a stationary filter cleaner.
It is still another object of the subject invention to provide an air inlet filter that does not add significantly to the axial length of the gas turbine engine to which it is connected.
Another object of the subject invention is to provide an air inlet filter and turbine engine with no ducting therebetween.
A further object of the subject invention is to provide air inlet filter assembly that enables cleaning of the filter without interrupting the operation of the engine or the vehicle in which the engine is mounted.